Method of making light emitting device and light emitting device made thereof

Abstract

This disclosure discloses a method of making a light-emitting device. The method comprises forming a plurality of light-emitting chips, each of the light-emitting chips comprising an epitaxial structure and an electrode formed on the epitaxial structure; forming a protection layer on the electrode in each of the light-emitting chips; forming a plurality of light-emitting groups by collecting the light-emitting chips, wherein each of the light-emitting groups having substantially the same opto-electrical characteristics; forming a wavelength converted layer in each of the light-emitting groups to cover the epitaxial structure and the protection layer; and removing the wavelength converted layer on the protection layer to expose the protection layer.

1 .- 11 . (canceled) 
     
     
         12 . A light-emitting device comprising:
 a substrate;   a light-emitting stack formed on the substrate and having a top region;   a wavelength converted layer formed on the light-emitting stack and has a first portion covering the top region of the light-emitting stack and a second portion protruding from the first portion with a first distance.   
     
     
         13 . The light-emitting device of  claim 12 , wherein the first distance ranges from 10 μm to 70 μm. 
     
     
         14 . The light-emitting device of  claim 12 , wherein the second portion has a width less than that of the first portion. 
     
     
         15 . The light-emitting device of  claim 12 , wherein each of the substrate and the light-emitting stack has a side region, and the wavelength converted layer covering and the side region of the substrate and the light-emitting stack. 
     
     
         16 . The light-emitting device of  claim 15 , wherein the wavelength converted layer on the side region has a width smaller than a thickness of the wavelength converted layer on the top region. 
     
     
         17 . The light-emitting device of  claim 13 , wherein the wavelength converted layer covering the top region of the light-emitting stack is spaced apart from the electrode with a second distance ranging from 1 to 10 μm. 
     
     
         18 . The light-emitting device of  claim 13 , further comprising an electrode and a metal bump, wherein the metal bump is formed on a top surface of the electrode and has a sidewall and a top surface, and wherein the wavelength converted layer surrounds the sidewall without covering the top surface. 
     
     
         19 . The light-emitting device of  claim 18 , further comprising a wire electrically connecting with the metal bump, and wherein the wavelength converted layer does not cover the wire. 
     
     
         20 . A light-emitting device comprising:
 a substrate having a top surface, a bottom surface, and four side regions between the top and bottom surfaces;   a light-emitting stack on the top surface of the substrate and having a top region;   a metal bump electrically coupled to the light-emitting stack; and   a wavelength converted layer formed on the four side regions and the top region of the light-emitting stack without covering the metal bump.   
     
     
         21 . A method of making a light-emitting diode, comprising:
 preparing a plurality of light-emitting chips, one of the plurality of light-emitting chips comprising an electrode and a protection layer covering the electrode;   forming a wavelength conversion layer on the protection layer after covering the electrode; and   exposing the electrode after forming the wavelength conversion layer.   
     
     
         22 . The method of  claim 21 , wherein the plurality of light-emitting chips have an emission wavelength difference smaller than 10 nm. 
     
     
         23 . The method of  claim 21 , wherein the plurality of light-emitting chips have a forward voltage difference less than 0.4V. 
     
     
         24 . The method of  claim 21 , wherein the preparing step comprises separating a plurality of light-emitting units after the protection layer is formed on the electrode. 
     
     
         25 . The method of  claim 24 , wherein the plurality of light-emitting units are commonly formed on a wafer. 
     
     
         26 . The method of  claim 24 , wherein the plurality of light-emitting units comprises a first light-emitting unit formed on a first wafer, and a second light-emitting unit formed on a second wafer. 
     
     
         27 . The method of  claim 21 , wherein the exposing step comprises partially removing the wavelength conversion layer. 
     
     
         28 . The method of  claim 21 , wherein the exposing step comprises substantially removing the protection layer. 
     
     
         29 . The method of  claim 21 , wherein the exposing step comprises exposing the protection layer. 
     
     
         30 . The method of  claim 21 , further comprising a step of removing a part of the protection layer before forming the wavelength conversion layer. 
     
     
         31 . The method of  claim 21 , wherein the electrode is surrounded by the wavelength conversion layer. 
     
     
         32 . The method of  claim 21 , wherein the electrode has a top surface which is entirely exposed at the exposing step. 
     
     
         33 . The method of  claim 21 , wherein the one of the plurality of light-emitting chips further comprises an epitaxial structure which is not covered by the protection layer before forming the wavelength conversion layer. 
     
     
         34 . A method of making a light-emitting diode, comprising:
 preparing a plurality of light-emitting units which are connected with each other, one of the plurality of light-emitting units comprising an epitaxial structure and an electrode;   forming a protection layer on the electrode;   disconnecting the plurality of light-emitting units from each other; and   removing the protection layer to substantially expose the electrode.   
     
     
         35 . The method of  claim 34 , further comprising a step of forming a wavelength conversion layer on the protection layer. 
     
     
         36 . The method of  claim 34 , wherein the electrode has a top surface which is entirely exposed after the removing step. 
     
     
         37 . The method of  claim 34 , wherein the removing step comprises using a solvent of N-methyl-2-pyrrolidone. 
     
     
         38 . The method of  claim 34 , wherein the removing step is conducted after the disconnecting step. 
     
     
         39 . The method of  claim 34 , wherein the epitaxial structure is substantially not covered by the protection layer. 
     
     
         40 . The method of  claim 34 , further comprising a step of grouping a part of the plurality of light-emitting units into a light-emitting group before the removing step.